Image from on board the John Calvin in the NE trades, en route to Australia. Painted by convict Kanute Bull in Charles Bateson: The Convict Ships
Embarked: 199 men
Voyage: 131 days
Surgeon's Journal: Yes
Master: R.L. Hunter
Surgeon Superintendent Henry Kelsall
By the time to following news was received in Australia in September 1846, the John Calvin was already on the eve of arrival at Norfolk Island.....
The Times of April 30 states that the Commandant of Chatham Garrison, Col. Sir T. Wilshire, K.C.B. has directed the officer in command of the 65th regiment Lieut-Col C.E. Gold to select a detachment of his corps consisting of three sergeants three corporals and forty four privates and to hold themselves in readiness to embark at Woolwich on the 3rd of May on board the John Calvin convict ship as a convict guard to proceed in charge of convicts for Norfolk Island. Captain St. Leger Barry, with Lieutenant George Meyler, 65th regiment are the officers selected to take the command of the guard. Six women and eight children accompany the detachment. The troops women, and children undergo medical inspection this day. 
George Freeman Murray later replaced Captain St. Leger Barry on the John Calvin. The Guard consisted of 50 rank and file 65th regiment, 7 women and 7 children.
Passengers included Mrs. Murray and 4 children and Mr. Collett, Religious Instructor;
Surgeon Henry Kelsall
Henry Kelsall kept a medical journal from 4th May 1846 to 8th October 1846. It is an interesting journal as he makes note of the 20 or so cases of epileptic fits that took place at the beginning of the voyage. There were two long standing cases of epilepsy amongst the prisoners, however those cases that occurred in the first few days on board with so many other young men were temporary and perhaps an hysterical reaction to the trauma of all they were experiencing
4th May 1846 - The Guard for the John Calvin convict ship embarked at Woolwich consisting of 50 men of the 65th regiment and 2 Officers 9 women and 12 children
5th May 199 male convicts from Milbank prison were embarked for transportation to Norfolk island in a clean and healthy state; the majority of them being young men from 17 to 35 years of age of which a great many ranged from 19 to 23 years old. These had all been confined in separate cells of the Milbank prison for different periods varying from a month to three or four months. On the first night after their embarkation nothing particular occurred but on the day following three or four convicts were seized with epileptic fits and when locked down at sunset about 16 or 17 fresh cases of epilepsy occurred in the prison, the patients quickly recovering on being sluiced with cold water - during that night and the following day about 20 others were similarly attacked besides several who had fallen down yesterday. Nearly all of these men declared they had never suffered epileptic fits before and as I do not myself think they were feigning the disease it is probable that the sudden change from long continued solitary confinement to the bustle of a crowded ship conjoined to depression of mind natural to me in their situation may have occasioned the state of things here related. The symptoms were as follows - insensibility, violent action of all the muscles - frothing at the mouth - blueness of the lips - and in several instances the tongue was lacerated from the grinding of that member between the teeth. After the convicts had been on board five days there were no more epileptic patients with the exception of two who had all their lives been subject to epileptic fits.
13th May - The John Calvin sailed from Woolwich- put into Spithead in consequence of foul wind 
21st May - sailed from Spithead
21st September 1846 arrived at Norfolk Island.
22nd September - The whole of the prisoners were disembarked in good health. The ship then proceeded to Hobart Town 
6th October 1846 - arrived in Hobart
8th October 1846 - The Guard and guard's families were disembarked in Hobart. One child aged three years having died on 24th August. Previous to sailing from Spithead a supply of fresh beef and vegetables was sent on board by order of the Admiral Superintendent which served the convicts three days and the guard four days. No appearance of scurvy manifested itself amongst the guard or convicts during the voyage and indeed any sickness of importance. The ship was kept dry by holystoning the decks and swinging stoves. The prevailing complains were ophthalmic, seven cases of ringworm and one case of fever. 
Notes and Links
1). Knud Geelmuyden Bull - Design and Art Australia Online
2). George Freeman Murray of the 65th Regiment
 Sydney Morning Herald 9 September 1846
 Medical Journal of Henry Kelsall on the voyage of the John Calvin in 1846. Ancestry.com. UK, Royal Navy Medical Journals, 1817-1857. Original data: The National Archives. Kew, Richmond, Surrey.